'\" t
.TH "SYSTEMD\-RUN" "1" "" "systemd 257.1" "systemd-run"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
systemd-run \- Run programs in transient scope units, service units, or path\-, socket\-, or timer\-triggered service units
.SH "SYNOPSIS"
.HP \w'\fBsystemd\-run\fR\ 'u
\fBsystemd\-run\fR [OPTIONS...] \fICOMMAND\fR\ [ARGS...] 
.HP \w'\fBsystemd\-run\fR\ 'u
\fBsystemd\-run\fR [OPTIONS...] [PATH\ OPTIONS...] {\fICOMMAND\fR} [ARGS...]
.HP \w'\fBsystemd\-run\fR\ 'u
\fBsystemd\-run\fR [OPTIONS...] [SOCKET\ OPTIONS...] {\fICOMMAND\fR} [ARGS...]
.HP \w'\fBsystemd\-run\fR\ 'u
\fBsystemd\-run\fR [OPTIONS...] [TIMER\ OPTIONS...] {\fICOMMAND\fR} [ARGS...]
.SH "DESCRIPTION"
.PP
\fBsystemd\-run\fR
may be used to create and start a transient
\&.service
or
\&.scope
unit and run the specified
\fICOMMAND\fR
in it\&. It may also be used to create and start a transient
\&.path,
\&.socket, or
\&.timer
unit, that activates a
\&.service
unit when elapsing\&.
.PP
If a command is run as transient service unit, it will be started and managed by the service manager like any other service, and thus shows up in the output of
\fBsystemctl list\-units\fR
like any other unit\&. It will run in a clean and detached execution environment, with the service manager as its parent process\&. In this mode,
\fBsystemd\-run\fR
will start the service asynchronously in the background and return after the command has begun execution (unless
\fB\-\-no\-block\fR,
\fB\-\-wait\fR,
\fB\-\-pipe\fR, or
\fB\-\-pty\fR
are specified, see below)\&.
.PP
If a command is run as transient scope unit, it will be executed by
\fBsystemd\-run\fR
itself as parent process and will thus inherit the execution environment of the caller\&. However, the processes of the command are managed by the service manager similarly to normal services, and will show up in the output of
\fBsystemctl list\-units\fR\&. Execution in this case is synchronous, and will return only when the command finishes\&. This mode is enabled via the
\fB\-\-scope\fR
switch (see below)\&.
.PP
If a command is run with path, socket, or timer options such as
\fB\-\-on\-calendar=\fR
(see below), a transient path, socket, or timer unit is created alongside the service unit for the specified command\&. Only the transient path, socket, or timer unit is started immediately, the transient service unit will be triggered by the path, socket, or timer unit\&. If the
\fB\-\-unit=\fR
option is specified, the
\fICOMMAND\fR
may be omitted\&. In this case,
\fBsystemd\-run\fR
creates only a
\&.path,
\&.socket, or
\&.timer
unit that triggers the specified unit\&.
.PP
By default, services created with
\fBsystemd\-run\fR
default to the
\fBsimple\fR
type, see the description of
\fIType=\fR
in
\fBsystemd.service\fR(5)
for details\&. Note that when this type is used, the service manager (and thus the
\fBsystemd\-run\fR
command) considers service start\-up successful as soon as the
\fBfork()\fR
for the main service process succeeded, i\&.e\&. before the
\fBexecve()\fR
is invoked, and thus even if the specified command cannot be started\&. Consider using the
\fBexec\fR
service type (i\&.e\&.
\fB\-\-property=Type=exec\fR) to ensure that
\fBsystemd\-run\fR
returns successfully only if the specified command line has been successfully started\&.
.PP
After
\fBsystemd\-run\fR
passes the command to the service manager, the manager performs variable expansion\&. This means that dollar characters ("$") which should not be expanded need to be escaped as
"$$"\&. Expansion can also be disabled using
\fI\-\-expand\-environment=no\fR\&.
.SH "OPTIONS"
.PP
The following options are understood:
.PP
\fB\-\-scope\fR
.RS 4
Create a transient
\&.scope
unit instead of the default transient
\&.service
unit (see above)\&.
.sp
Added in version 206\&.
.RE
.PP
\fB\-\-unit=\fR, \fB\-u\fR
.RS 4
Use this unit name instead of an automatically generated one\&.
.sp
Added in version 206\&.
.RE
.PP
\fB\-\-property=\fR, \fB\-p\fR
.RS 4
Sets a property on the scope or service unit that is created\&. This option takes an assignment in the same format as
\fBsystemctl\fR(1)\*(Aqs
\fBset\-property\fR
command\&.
.sp
Added in version 211\&.
.RE
.PP
\fB\-\-description=\fR
.RS 4
Provide a description for the service, scope, path, socket, or timer unit\&. If not specified, the command itself will be used as a description\&. See
\fIDescription=\fR
in
\fBsystemd.unit\fR(5)\&.
.sp
Added in version 206\&.
.RE
.PP
\fB\-\-slice=\fR
.RS 4
Make the new
\&.service
or
\&.scope
unit part of the specified slice, instead of
system\&.slice
(when running in
\fB\-\-system\fR
mode) or the root slice (when running in
\fB\-\-user\fR
mode)\&.
.sp
Added in version 206\&.
.RE
.PP
\fB\-\-slice\-inherit\fR
.RS 4
Make the new
\&.service
or
\&.scope
unit part of the slice the
\fBsystemd\-run\fR
itself has been invoked in\&. This option may be combined with
\fB\-\-slice=\fR, in which case the slice specified via
\fB\-\-slice=\fR
is placed within the slice the
\fBsystemd\-run\fR
command is invoked in\&.
.sp
Example: consider
\fBsystemd\-run\fR
being invoked in the slice
foo\&.slice, and the
\fB\-\-slice=\fR
argument is
bar\&. The unit will then be placed under
foo\-bar\&.slice\&.
.sp
Added in version 246\&.
.RE
.PP
\fB\-\-expand\-environment=\fR\fB\fIBOOL\fR\fR
.RS 4
Expand environment variables in command arguments\&. If enabled, environment variables specified as
"${\fIVARIABLE\fR}"
will be expanded in the same way as in commands specified via
\fIExecStart=\fR
in units\&. With
\fI\-\-scope\fR, this expansion is performed by
\fBsystemd\-run\fR
itself, and in other cases by the service manager that spawns the command\&. Note that this is similar to, but not the same as variable expansion in
\fBbash\fR(1)
and other shells\&.
.sp
The default is to enable this option in all cases, except for
\fI\-\-scope\fR
where it is disabled by default, for backward compatibility reasons\&. Note that this will be changed in a future release, where it will be switched to enabled by default as well\&.
.sp
See
\fBsystemd.service\fR(5)
for a description of variable expansion\&. Disabling variable expansion is useful if the specified command includes or may include a
"$"
sign\&.
.sp
Added in version 254\&.
.RE
.PP
\fB\-r\fR, \fB\-\-remain\-after\-exit\fR
.RS 4
After the service process has terminated, keep the service around until it is explicitly stopped\&. This is useful to collect runtime information about the service after it finished running\&. Also see
\fIRemainAfterExit=\fR
in
\fBsystemd.service\fR(5)\&.
.sp
Added in version 207\&.
.RE
.PP
\fB\-\-send\-sighup\fR
.RS 4
When terminating the scope or service unit, send a SIGHUP immediately after SIGTERM\&. This is useful to indicate to shells and shell\-like processes that the connection has been severed\&. Also see
\fISendSIGHUP=\fR
in
\fBsystemd.kill\fR(5)\&.
.sp
Added in version 207\&.
.RE
.PP
\fB\-\-service\-type=\fR
.RS 4
Sets the service type\&. Also see
\fIType=\fR
in
\fBsystemd.service\fR(5)\&. This option has no effect in conjunction with
\fB\-\-scope\fR\&. Defaults to
\fBsimple\fR\&.
.sp
Added in version 211\&.
.RE
.PP
\fB\-\-uid=\fR, \fB\-\-gid=\fR
.RS 4
Runs the service process under the specified UNIX user and group\&. Also see
\fIUser=\fR
and
\fIGroup=\fR
in
\fBsystemd.exec\fR(5)\&.
.sp
Added in version 211\&.
.RE
.PP
\fB\-\-nice=\fR
.RS 4
Runs the service process with the specified nice level\&. Also see
\fINice=\fR
in
\fBsystemd.exec\fR(5)\&.
.sp
Added in version 211\&.
.RE
.PP
\fB\-\-working\-directory=\fR
.RS 4
Runs the service process with the specified working directory\&. Also see
\fIWorkingDirectory=\fR
in
\fBsystemd.exec\fR(5)\&.
.sp
Added in version 240\&.
.RE
.PP
\fB\-\-same\-dir\fR, \fB\-d\fR
.RS 4
Similar to
\fB\-\-working\-directory=\fR, but uses the current working directory of the caller for the service to execute\&.
.sp
Added in version 240\&.
.RE
.PP
\fB\-E \fR\fB\fINAME\fR\fR\fB[=\fR\fB\fIVALUE\fR\fR\fB]\fR, \fB\-\-setenv=\fR\fB\fINAME\fR\fR\fB[=\fR\fB\fIVALUE\fR\fR\fB]\fR
.RS 4
Runs the service process with the specified environment variable set\&. This parameter may be used more than once to set multiple variables\&. When
"="
and
\fIVALUE\fR
are omitted, the value of the variable with the same name in the program environment will be used\&.
.sp
Also see
\fIEnvironment=\fR
in
\fBsystemd.exec\fR(5)\&.
.sp
Added in version 211\&.
.RE
.PP
\fB\-\-pty\fR, \fB\-t\fR
.RS 4
When invoking the command, the transient service connects its standard input, output and error to the terminal
\fBsystemd\-run\fR
is invoked on, via a pseudo TTY device\&. This allows running programs that expect interactive user input/output as services, such as interactive command shells\&.
.sp
This option will result in
\fBsystemd\-run\fR
synchronously waiting for the transient service to terminate, similar to specifying
\fB\-\-wait\fR\&. If specified along with
\fB\-\-wait\fR,
\fBsystemd\-run\fR
won\*(Aqt exit when manually disconnecting from the pseudo TTY device\&.
.sp
Note that
\fBmachinectl\fR(1)\*(Aqs
\fBshell\fR
command is usually a better alternative for requesting a new, interactive login session on the local host or a local container\&.
.sp
See below for details on how this switch combines with
\fB\-\-pipe\fR\&.
.sp
Added in version 219\&.
.RE
.PP
\fB\-\-pipe\fR, \fB\-P\fR
.RS 4
If specified, standard input, output, and error of the transient service are inherited from the
\fBsystemd\-run\fR
command itself\&. This allows
\fBsystemd\-run\fR
to be used within shell pipelines\&.
.sp
Note that this mode is not suitable for interactive command shells and similar, as the service process will not become a TTY controller when invoked on a terminal\&. Use
\fB\-\-pty\fR
instead in that case\&.
.sp
When both
\fB\-\-pipe\fR
and
\fB\-\-pty\fR
are used in combination the more appropriate option is automatically determined and used\&. Specifically, when invoked with standard input, output and error connected to a TTY
\fB\-\-pty\fR
is used, and otherwise
\fB\-\-pipe\fR\&.
.sp
This option will result in
\fBsystemd\-run\fR
synchronously waiting for the transient service to terminate, similar to specifying
\fB\-\-wait\fR\&.
.sp
When this option is used the original file descriptors
\fBsystemd\-run\fR
receives are passed to the service processes as\-is\&. If the service runs with different privileges than
\fBsystemd\-run\fR, this means the service might not be able to reopen the passed file descriptors, due to normal file descriptor access restrictions\&. If the invoked process is a shell script that uses the
\fBecho "hello" >/dev/stderr\fR
construct for writing messages to stderr, this might cause problems, as this only works if stderr can be reopened\&. To mitigate this use the construct
\fBecho "hello" >&2\fR
instead, which is mostly equivalent and avoids this pitfall\&.
.sp
Added in version 235\&.
.RE
.PP
\fB\-\-shell\fR, \fB\-S\fR
.RS 4
A shortcut for
"\-\-pty \-\-same\-dir \-\-wait \-\-collect \-\-service\-type=exec $SHELL", i\&.e\&. requests an interactive shell in the current working directory, running in service context, accessible with a single switch\&.
.sp
Added in version 240\&.
.RE
.PP
\fB\-\-quiet\fR, \fB\-q\fR
.RS 4
Suppresses additional informational output while running\&. This is particularly useful in combination with
\fB\-\-pty\fR
when it will suppress the initial message explaining how to terminate the TTY connection\&.
.sp
Added in version 219\&.
.RE
.PP
\fB\-\-on\-active=\fR, \fB\-\-on\-boot=\fR, \fB\-\-on\-startup=\fR, \fB\-\-on\-unit\-active=\fR, \fB\-\-on\-unit\-inactive=\fR
.RS 4
Defines a monotonic timer relative to different starting points for starting the specified command\&. See
\fIOnActiveSec=\fR,
\fIOnBootSec=\fR,
\fIOnStartupSec=\fR,
\fIOnUnitActiveSec=\fR
and
\fIOnUnitInactiveSec=\fR
in
\fBsystemd.timer\fR(5)
for details\&. These options are shortcuts for
\fB\-\-timer\-property=\fR
with the relevant properties\&. These options may not be combined with
\fB\-\-scope\fR
or
\fB\-\-pty\fR\&.
.sp
Added in version 218\&.
.RE
.PP
\fB\-\-on\-calendar=\fR
.RS 4
Defines a calendar timer for starting the specified command\&. See
\fIOnCalendar=\fR
in
\fBsystemd.timer\fR(5)\&. This option is a shortcut for
\fB\-\-timer\-property=OnCalendar=\fR\&. This option may not be combined with
\fB\-\-scope\fR
or
\fB\-\-pty\fR\&.
.sp
Added in version 218\&.
.RE
.PP
\fB\-\-on\-clock\-change\fR, \fB\-\-on\-timezone\-change\fR
.RS 4
Defines a trigger based on system clock jumps or timezone changes for starting the specified command\&. See
\fIOnClockChange=\fR
and
\fIOnTimezoneChange=\fR
in
\fBsystemd.timer\fR(5)\&. These options are shortcuts for
\fB\-\-timer\-property=OnClockChange=yes\fR
and
\fB\-\-timer\-property=OnTimezoneChange=yes\fR\&. These options may not be combined with
\fB\-\-scope\fR
or
\fB\-\-pty\fR\&.
.sp
Added in version 242\&.
.RE
.PP
\fB\-\-path\-property=\fR, \fB\-\-socket\-property=\fR, \fB\-\-timer\-property=\fR
.RS 4
Sets a property on the path, socket, or timer unit that is created\&. This option is similar to
\fB\-\-property=\fR, but applies to the transient path, socket, or timer unit rather than the transient service unit created\&. This option takes an assignment in the same format as
\fBsystemctl\fR(1)\*(Aqs
\fBset\-property\fR
command\&. These options may not be combined with
\fB\-\-scope\fR
or
\fB\-\-pty\fR\&.
.sp
Added in version 218\&.
.RE
.PP
\fB\-\-no\-block\fR
.RS 4
Do not synchronously wait for the unit start operation to finish\&. If this option is not specified, the start request for the transient unit will be verified, enqueued and
\fBsystemd\-run\fR
will wait until the unit\*(Aqs start\-up is completed\&. By passing this argument, it is only verified and enqueued\&. This option may not be combined with
\fB\-\-wait\fR\&.
.sp
Added in version 220\&.
.RE
.PP
\fB\-\-wait\fR
.RS 4
Synchronously wait for the transient service to terminate\&. If this option is specified, the start request for the transient unit is verified, enqueued, and waited for\&. Subsequently the invoked unit is monitored, and it is waited until it is deactivated again (most likely because the specified command completed)\&. On exit, terse information about the unit\*(Aqs runtime is shown, including total runtime (as well as CPU usage, if
\fB\-\-property=CPUAccounting=1\fR
was set) and the exit code and status of the main process\&. This output may be suppressed with
\fB\-\-quiet\fR\&. This option may not be combined with
\fB\-\-no\-block\fR,
\fB\-\-scope\fR
or the various path, socket, or timer options\&.
.sp
Added in version 232\&.
.RE
.PP
\fB\-G\fR, \fB\-\-collect\fR
.RS 4
Unload the transient unit after it completed, even if it failed\&. Normally, without this option, all units that ran and failed are kept in memory until the user explicitly resets their failure state with
\fBsystemctl reset\-failed\fR
or an equivalent command\&. On the other hand, units that ran successfully are unloaded immediately\&. If this option is turned on the "garbage collection" of units is more aggressive, and unloads units regardless if they exited successfully or failed\&. This option is a shortcut for
\fB\-\-property=CollectMode=inactive\-or\-failed\fR, see the explanation for
\fICollectMode=\fR
in
\fBsystemd.unit\fR(5)
for further information\&.
.sp
Added in version 236\&.
.RE
.PP
\fB\-\-ignore\-failure\fR
.RS 4
By default, if the specified command fails the invoked unit will be marked failed (though possibly still unloaded, see
\fB\-\-collect=\fR, above), and this is reported in the logs\&. If this switch is specified this is suppressed and any non\-success exit status/code of the command is treated as success\&.
.sp
Added in version 256\&.
.RE
.PP
\fB\-\-background=\fR\fB\fICOLOR\fR\fR
.RS 4
Change the terminal background color to the specified ANSI color as long as the session lasts\&. The color specified should be an ANSI X3\&.64 SGR background color, i\&.e\&. strings such as
"40",
"41", \&...,
"47",
"48;2;\&...",
"48;5;\&..."\&. See
\m[blue]\fBANSI Escape Code (Wikipedia)\fR\m[]\&\s-2\u[1]\d\s+2
for details\&.
.sp
Added in version 256\&.
.RE
.PP
\fB\-\-user\fR
.RS 4
Talk to the service manager of the calling user, rather than the service manager of the system\&.
.RE
.PP
\fB\-\-system\fR
.RS 4
Talk to the service manager of the system\&. This is the implied default\&.
.RE
.PP
\fB\-H\fR, \fB\-\-host=\fR
.RS 4
Execute the operation remotely\&. Specify a hostname, or a username and hostname separated by
"@", to connect to\&. The hostname may optionally be suffixed by a port ssh is listening on, separated by
":", and then a container name, separated by
"/", which connects directly to a specific container on the specified host\&. This will use SSH to talk to the remote machine manager instance\&. Container names may be enumerated with
\fBmachinectl \-H \fR\fB\fIHOST\fR\fR\&. Put IPv6 addresses in brackets\&.
.RE
.PP
\fB\-M\fR, \fB\-\-machine=\fR
.RS 4
Execute operation on a local container\&. Specify a container name to connect to, optionally prefixed by a user name to connect as and a separating
"@"
character\&. If the special string
"\&.host"
is used in place of the container name, a connection to the local system is made (which is useful to connect to a specific user\*(Aqs user bus:
"\-\-user \-\-machine=lennart@\&.host")\&. If the
"@"
syntax is not used, the connection is made as root user\&. If the
"@"
syntax is used either the left hand side or the right hand side may be omitted (but not both) in which case the local user name and
"\&.host"
are implied\&.
.RE
.PP
\fB\-C\fR, \fB\-\-capsule=\fR
.RS 4
Execute operation on a capsule\&. Specify a capsule name to connect to\&. See
\fBcapsule@.service\fR(5)
for details about capsules\&.
.sp
Added in version 256\&.
.RE
.PP
\fB\-\-no\-ask\-password\fR
.RS 4
Do not query the user for authentication for privileged operations\&.
.RE
.PP
\fB\-h\fR, \fB\-\-help\fR
.RS 4
Print a short help text and exit\&.
.RE
.PP
\fB\-\-version\fR
.RS 4
Print a short version string and exit\&.
.RE
.PP
\fB\-\-json=\fR\fB\fIMODE\fR\fR
.RS 4
Shows output formatted as JSON\&. Expects one of
"short"
(for the shortest possible output without any redundant whitespace or line breaks),
"pretty"
(for a pretty version of the same, with indentation and line breaks) or
"off"
(to turn off JSON output, the default)\&.
.RE
.PP
All command line arguments after the first non\-option argument become part of the command line of the launched process\&.
.SH "EXIT STATUS"
.PP
On success, 0 is returned\&. If
\fBsystemd\-run\fR
failed to start the service, a non\-zero return value will be returned\&. If
\fBsystemd\-run\fR
waits for the service to terminate, the return value will be propagated from the service\&. 0 will be returned on success, including all the cases where systemd considers a service to have exited cleanly, see the discussion of
\fISuccessExitStatus=\fR
in
\fBsystemd.service\fR(5)\&.
.SH "EXAMPLES"
.PP
\fBExample\ \&1.\ \&Logging environment variables provided by systemd to services\fR
.sp
.if n \{\
.RS 4
.\}
.nf
# systemd\-run env
Running as unit: run\-19945\&.service
# journalctl \-u run\-19945\&.service
Sep 08 07:37:21 bupkis systemd[1]: Starting /usr/bin/env\&.\&.\&.
Sep 08 07:37:21 bupkis systemd[1]: Started /usr/bin/env\&.
Sep 08 07:37:21 bupkis env[19948]: PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
Sep 08 07:37:21 bupkis env[19948]: LANG=en_US\&.UTF\-8
Sep 08 07:37:21 bupkis env[19948]: BOOT_IMAGE=/vmlinuz\-3\&.11\&.0\-0\&.rc5\&.git6\&.2\&.fc20\&.x86_64
.fi
.if n \{\
.RE
.\}
.PP
\fBExample\ \&2.\ \&Limiting resources available to a command\fR
.sp
.if n \{\
.RS 4
.\}
.nf
# systemd\-run \-p IOWeight=10 updatedb
.fi
.if n \{\
.RE
.\}
.PP
This command invokes the
\fBupdatedb\fR(8)
tool, but lowers the block I/O weight for it to 10\&. See
\fBsystemd.resource-control\fR(5)
for more information on the
\fIIOWeight=\fR
property\&.
.PP
\fBExample\ \&3.\ \&Running commands at a specified time\fR
.PP
The following command will touch a file after 30 seconds\&.
.sp
.if n \{\
.RS 4
.\}
.nf
# date; systemd\-run \-\-on\-active=30 \-\-timer\-property=AccuracySec=100ms /bin/touch /tmp/foo
Mon Dec  8 20:44:24 KST 2014
Running as unit: run\-71\&.timer
Will run service as unit: run\-71\&.service
# journalctl \-b \-u run\-71\&.timer
\-\- Journal begins at Fri 2014\-12\-05 19:09:21 KST, ends at Mon 2014\-12\-08 20:44:54 KST\&. \-\-
Dec 08 20:44:38 container systemd[1]: Starting /bin/touch /tmp/foo\&.
Dec 08 20:44:38 container systemd[1]: Started /bin/touch /tmp/foo\&.
# journalctl \-b \-u run\-71\&.service
\-\- Journal begins at Fri 2014\-12\-05 19:09:21 KST, ends at Mon 2014\-12\-08 20:44:54 KST\&. \-\-
Dec 08 20:44:48 container systemd[1]: Starting /bin/touch /tmp/foo\&.\&.\&.
Dec 08 20:44:48 container systemd[1]: Started /bin/touch /tmp/foo\&.
.fi
.if n \{\
.RE
.\}
.PP
\fBExample\ \&4.\ \&Allowing access to the tty\fR
.PP
The following command invokes
\fBbash\fR(1)
as a service passing its standard input, output and error to the calling TTY\&.
.sp
.if n \{\
.RS 4
.\}
.nf
# systemd\-run \-t \-\-send\-sighup bash
.fi
.if n \{\
.RE
.\}
.PP
\fBExample\ \&5.\ \&Start screen as a user service\fR
.sp
.if n \{\
.RS 4
.\}
.nf
$ systemd\-run \-\-scope \-\-user screen
Running scope as unit run\-r14b0047ab6df45bfb45e7786cc839e76\&.scope\&.

$ screen \-ls
There is a screen on:
        492\&.\&.laptop     (Detached)
1 Socket in /var/run/screen/S\-fatima\&.
.fi
.if n \{\
.RE
.\}
.PP
This starts the
\fBscreen\fR
process as a child of the
\fBsystemd \-\-user\fR
process that was started by
user@\&.service, in a scope unit\&. A
\fBsystemd.scope\fR(5)
unit is used instead of a
\fBsystemd.service\fR(5)
unit, because
\fBscreen\fR
will exit when detaching from the terminal, and a service unit would be terminated\&. Running
\fBscreen\fR
as a user unit has the advantage that it is not part of the session scope\&. If
\fIKillUserProcesses=yes\fR
is configured in
\fBlogind.conf\fR(5), the default, the session scope will be terminated when the user logs out of that session\&.
.PP
The
user@\&.service
is started automatically when the user first logs in, and stays around as long as at least one login session is open\&. After the user logs out of the last session,
user@\&.service
and all services underneath it are terminated\&. This behavior is the default, when "lingering" is not enabled for that user\&. Enabling lingering means that
user@\&.service
is started automatically during boot, even if the user is not logged in, and that the service is not terminated when the user logs out\&.
.PP
Enabling lingering allows the user to run processes without being logged in, for example to allow
\fBscreen\fR
to persist after the user logs out, even if the session scope is terminated\&. In the default configuration, users can enable lingering for themselves:
.sp
.if n \{\
.RS 4
.\}
.nf
$ loginctl enable\-linger
.fi
.if n \{\
.RE
.\}
.PP
\fBExample\ \&6.\ \&Variable expansion by the manager\fR
.sp
.if n \{\
.RS 4
.\}
.nf
$ systemd\-run \-t echo "<${INVOCATION_ID}>" \*(Aq<${INVOCATION_ID}>\*(Aq
      <> <5d0149bfa2c34b79bccb13074001eb20>
.fi
.if n \{\
.RE
.\}
.PP
The first argument is expanded by the shell (double quotes), but the second one is not expanded by the shell (single quotes)\&.
\fBecho\fR(1)
is called with ["/usr/bin/echo",
"<>",
"<${INVOCATION_ID}>"] as the argument array, and then
\fBsystemd\fR(1)
generates
\fI${INVOCATION_ID}\fR
and substitutes it in the command\-line\&. This substitution could not be done on the client side, because the target ID that will be set for the service isn\*(Aqt known before the call is made\&.
.PP
\fBExample\ \&7.\ \&Variable expansion and output redirection using a shell\fR
.PP
Variable expansion by
\fBsystemd\fR(1)
can be disabled with
\fI\-\-expand\-environment=no\fR\&.
.PP
Disabling variable expansion can be useful if the command to execute contains dollar characters and escaping them would be inconvenient\&. For example, when a shell is used:
.sp
.if n \{\
.RS 4
.\}
.nf
$ systemd\-run \-\-expand\-environment=no \-t bash \e
      \-c \*(Aqecho $SHELL $$ >/dev/stdout\*(Aq
/bin/bash 12345
.fi
.if n \{\
.RE
.\}
.PP
The last argument is passed verbatim to the
\fBbash\fR(1)
shell which is started by the service unit\&. The shell expands
"$SHELL"
to the path of the shell, and
"$$"
to its process number, and then those strings are passed to the
\fBecho\fR
built\-in and printed to standard output (which in this case is connected to the calling terminal)\&.
.PP
\fBExample\ \&8.\ \&Return value\fR
.sp
.if n \{\
.RS 4
.\}
.nf
$ systemd\-run \-\-user \-\-wait true
$ systemd\-run \-\-user \-\-wait \-p SuccessExitStatus=11 bash \-c \*(Aqexit 11\*(Aq
$ systemd\-run \-\-user \-\-wait \-p SuccessExitStatus=SIGUSR1 \-\-expand\-environment=no \e
      bash \-c \*(Aqkill \-SIGUSR1 $$\*(Aq
.fi
.if n \{\
.RE
.\}
.PP
Those three invocations will succeed, i\&.e\&. terminate with an exit code of 0\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1), \fBsystemctl\fR(1), \fBsystemd.unit\fR(5), \fBsystemd.service\fR(5), \fBsystemd.scope\fR(5), \fBsystemd.slice\fR(5), \fBsystemd.exec\fR(5), \fBsystemd.resource-control\fR(5), \fBsystemd.timer\fR(5), \fBsystemd-mount\fR(1), \fBmachinectl\fR(1), \fBrun0\fR(1)
.SH "NOTES"
.IP " 1." 4
ANSI Escape Code (Wikipedia)
.RS 4
\%https://en.wikipedia.org/wiki/ANSI_escape_code#SGR_(Select_Graphic_Rendition)_parameters
.RE
